1. Field of the Invention
The present invention relates to an X-Y table and more particularly to an X-Y table used, for example, in semiconductor assembly machines.
2. Prior Art
Bonding devices used in producing semiconductors, etc. use a bonding head mounted on an X-Y table which moves on a horizontally two-dimensional plane. The X-Y table comprises a lower table and an upper table. The lower table moves in one direction on the horizontal plane, and the upper table installed on the lower table moves in the other direction on such a horizontal plane.
Several types of X-Y tables are disclosed in publications such as Japanese patent application publication (Kokoku) Nos. 59-52540 and 1-41466. These tables are for preventing adverse effects to the lower table feeding system. The adverse effect here is the one that is caused by the load generated by the feeding action of the upper table and applied onto a feed-driving means (e.g., feed screw, etc.) of the lower table.
In these X-Y tables, an upper table driving mechanism, which moves in the same direction as the feed direction of the upper table, is installed alongside the lower and upper tables for the purpose of feeding the upper table.
However, since the upper table driving mechanism is installed alongside the lower and upper tables, the installation area occupied by the X-Y table is increased. Such an increase of the installation area is typical when the X-Y table is used in a bonding apparatus.